A leading cause of mortality within the developed world is cardiovascular disease. Coronary disease is of most concern. Patients having such disease have narrowing in one or more coronary arteries. Generally, however, patients have narrowing in multiple coronary arteries. One treatment for the narrowing is stenting the blood vessel. Stenting involves the placement of a stent at the site of acute artery closure. This type of surgery has proved effective in restoring vessel patency and decreasing myocardial ischemia. However the exposure of currently used metallic stents to flowing blood can result in thrombus formation, smooth muscle cell proliferation and acute thrombotic occlusion of the stent.
Drug eluting stents (“DES”) generally result in lower restenosis and revascularization rates as compared to bare metal stents in vessels having a diameter greater than approximately 3.0 mm (“large vessels”). In addition to the challenges associated with large vessel stents, vessels having a diameter of less than 3.0 mm (“small vessels”) are clinically and angiographically at a disadvantage to larger vessels due to the inability of the small diameter to accommodate neointimal hyperplasia. These small-vessel DES have not led to significantly reduced late loss diameter or percent diameter stenosis like their large-vessel DES counterparts. The disclosed subject matter is particularly advantageous in that it is applicable to both large and small vessels.
A safety concern associated with drug-eluting stents is the occurrence of stent thrombosis. Dual Antiplatelet Therapy (“DAPT”), e.g., the administration of aspirin plus a second anti-clotting medication such as thienopyridine, is one accepted strategy for minimizing the risk of stent thrombosis. The literature suggests that premature DAPT discontinuation is associated with stent thrombosis. Therefore, to mitigate the risk of stent thrombosis, the current ACC/AHA/SCAI guideline recommends patients who receive a DES should be given aspirin indefinitely and thienopyridine for at least 12 months in the absence of increased risk of bleeding. Unfortunately, in real-world practice, patient non-compliance with DAPT therapy occurs due to adverse events, invasive surgery, patient non-compliance with the prescribed therapy, etc.
Accordingly, despite significant improvements in stent design, implantation equipment and techniques, and antiplatelet therapy, stent thrombosis remains to be one of the major safety concerns with drug-eluting stents. Thus, there remains a need for physicians to fully assess the risk of stent thrombosis, ranging from pre-implantation to post-implantation and medication compliance.